Compounds useful as pigments containing one or more 2,2,6,6-tetraalkylpiperidine groups

ABSTRACT

A pigment, which retains a crystal or particulate structure throughout a process of coloration of a substrate, containing one or more 2,2,6,6-tetraalkylpiperidine groups.

This application is a continuation-in-part of copending application Ser. No. 035,954, filed Apr. 8, 1987 now U.S. Pat. No. 4,838,943.

According to the invention there is provided a pigment, which retains a crystal or particulate structure throughout a process of colouration of a substrate, containing one or more 2,2,6,6-tetraalkylpiperidine groups.

For the avoidance of doubt, pigments are distinct from dyes. The Dry Colour Manufacturers Association (DCMA) have given a definition of pigments that differentiates them from dyes as follows.

Pigments are defined as "coloured, black, white or fluorescent particulate organic or inorganic solids, which are usually insoluble in and essentially physically and chemically unaffected by the vehicle or substrate in which they are incorporated. They alter appearance by selective absorption and/or by scattering of light. Pigments are usually dispersed in vehicles or substrates for application as, for instance, in the manufacture of inks, paints, plastics or other polymeric materials. Pigments retain a crystal or particulate structure throughout the colouration process."

Dyes have been defined, by the Dyes Environmental and Toxicity Organisation (DETO) as "intensely coloured or fluorescent organic substances only, which impart colour to a substrate by selective absorption of light. Dyes are . . . soluble and/or go through a process which, at least temporarily, destroys any crystal structure of the colour substances. Dyes are retained in the substrate by absorption, solution and mechanical retention or by ionic or covalent chemical bonds." (Abstracted from an article appearing in American Ink Maker, June, 1982).

Preferred pigments according to the invention are those of formula I or II ##STR1## in which R is hydrogen, C₁₋₈ alkyl, C₃₋₁₀ alkenyl, phenyl, phenyl- C₁₋₄ alkyl or --COR_(5a) where R_(5a) is hydrogen, --C(R_(10a))═CH₂, C₁₋₆ alkyl, phenyl, --COOC₁₋₄ alkyl or --NR₂₁ R₂₂, where R_(10a) is hydrogen or C₁₋₄ alkyl; R₂₁ is hydrogen, C₁₋₁₂ alkyl, C₅₋₆ cycloalkyl, phenyl, phenylC₁₋₄ alkyl or C₁₋₁₂ alkylphenyl and R₂₂ is C₁₋₁₂ alkyl or hydrogen;

each R₁ independently is --CH₃ or --CH₂ (C₁₋₄ alkyl) or both groups R₁ form a group --(CH₂)₅ --;

each R₂ independently is --CH₃ or --CH₂ (C₁₋₄ alkyl) or both groups R₂ form a group --(CH₂)₅ --;

R₄ is a direct bond or a bridging group; and

R₅ is hydrogen or C₁₋₄ alkyl; or

R₄ and R₅ together with the carbon atom to which they are attached form an isocyclic or heterocyclic bridging group;

R₆ is --NH₂, mono or di-C₁₋₄ alkylamino, C₁₋₂ alkylcarbonylamino, benzoylamino, hydrogen, OH or --CO--C₁₋₄ alkyl or --CO--C₁₋₄ alkoxy; and

R₇ is hydrogen or C₁₋₄ alkyl or

R₆ and R₇ together with the carbon atom to which they are attached form an isocyclic or heterocyclic ring;

R₈ is a direct bond or a bridging group;

D is a residue of a pigment; and

n is an integer from 1 to 4 inclusive.

For the avoidance of doubt, where a symbol appears more than once in a formula, its significances are independent of one another, unless indicated to the contrary.

When R₄ and R₅ together with the carbon atom to which they are attached form a heterocyclic or isocyclic ring, this ring is preferably a group of formula (a) or (b) ##STR2## the starred atom being attached to D.

When R₄ is a bridging group this is preferably *--NHCO--, *--NHSO₂ --, *--NH--CO--O--, *--NH--COCH₂ O--, *--NHCOCO--, --NHCOCONH--, *--NHCOCOO--, *--OCO--, *--OSO₂ --, *--OCOCO--, --OCO--CO--O--, *--OCONH-- or *--OCOCONH--, where the starred atom is attached to the piperidine ring.

When R₈ is a bridging group, this is preferably --CO--, --CH₂ *CO--, --OCH₂ *CO-- or --SO₂₋₋, where the starred atom is attached to the piperidine ring.

When R₆ and R₇ together with the carbon atom to which they are attached form a heterocyclic or isocyclic ring, this ring is preferably a group of formula (c) or (d) ##STR3## where R₁₂ is hydrogen, C₁₋₄ alkyl or C₁₋₄ alkoxycarbonyl-C₁₋₃ alkyl.

Preferably D is pigment residue of the azo, perinone, perilene, quinophthalone, isoindolinone, dioxazine, acetoacetyl amine, phthalocyanine or pyrrolo-pyrrole series.

When D is a pigment of the azo series, R₄ or R₈ of the compound of formula I or II respectively, may be attached either to the diazo component or to the coupling component. Preferably when D is a pigment residue of the azo series, it is a monoazo or disazo pigment residue.

More preferably D is D' where D' is a group of formula III to VIII when monovalent ##STR4## or D' is a group of formula IX to XV, when divalent ##STR5## or D' is a group of the formula XVI, when trivalent ##STR6## or D' is a group of the formula XVII, when tetravalent ##STR7## in which D₁ is 1,3- or 1,4-phenylene, unsubstituted or mono or di-substituted by substituents selected from the group consisting of chloro, bromo, C₁₋₂ alkyl, C₁₋₂ alkoxy, carboxy or C₁₋₄ alkoxycarbonyl; or 1,4, -1,5- or 1,8-anthraquinone, unsubstituted or mono or disubstituted by substituents selected from the group consisting of chloro, bromo, hydroxy, C₁₋₃ alkoxy or acylamino;

D₂ is phenyl, unsubstituted or substituted by one to three substituents, selected by the group consisting of chloro (max. 2), bromo (max. 2), C₁₋₂ alkoxy (max 2), C₁₋₄ alkoxy carbonyl (max 2) and acylamino (max 1);

D₃ is a 4,4'-diphenylene group, unsubstituted or substituted by one to four substituents selected from chloro, bromo, C₁₋₂ alkyl and C₁₋₂ alkoxy or is a group of formula ##STR8## where the starred atoms are attached to the azo in a group of formula VIII K₁ is a group of any one of formula K_(1a) to K_(1f) ##STR9## where the starred atom is attached to the azo group of IV or X; and R₁₆ is --O-- or --NH--;

K₂ is a group of any one of formula K_(2a) to K_(2c) ##STR10## K₃ is a group of any one of formula K_(3a) to K_(3g) ##STR11## in which R₁₀ is hydrogen, chloro, bromo, C₁₋₃ alkoxycarbonyl, C₁₋₂ alkyl, C₁₋₂ alkoxy or nitro;

R_(g) is 1,4-phenylene, unsubstituted or substituted by one or two groups selected from chloro, bromo, methyl or C₁₋₂ alkoxy; -4,4'-diphenylene; 1,4- or 1,5-naphthylene or a group of the formula ##STR12## where A is --CH₂ --, --NHCO--, --NHCONH--, --NH--CO--CO--NH-- or ##STR13## R₁₁ is methyl, --COOH or --COOC₁₋₄ alkyl; and R₁₇ is --OH, methyl or unsubstituted phenyl.

By the term "acyl" is preferably meant formyl, --COC₁₋₄ alkyl, --COC₁₋₄ alkoxy, or --CO--COO--C₁₋₄ alkyl. When D₁ or D₂ is substituted by acylamino, it is preferably --COC₁₋₄ -alkyl or --COC₁₋₄ alkoxy.

Preferably each R₁ and each R₂ is --CH₃.

Preferably R is R' where R' is hydrogen, methyl, formyl, C₁₋₄ alkylcarbonyl or --CO--CO--OC₁₋₄ alkyl.

Preferably R₄ is R₄ ' and R₅ is R₅ ' where R₄ ' is a direct bond, --NH--CO-- or --NH--CO--CH₂ --O-- and R₅ ' is hydrogen; or

R₄ ' and R₅ ' together with the carbon atom to which they are attached form a group of formula (a) or (b) defined above.

Preferably R₆ is R₆ ' and R₇ is R₇ ' where R₆ ' is --NH₂, mono-- or di--C₁₋₄ alkylamino, C₁₋₂ alkylcarbonylamino or benzoylamino and R₇ ' is hydrogen; or

R₆ ' and R₇ ' together with the carbon atom to which they are attached form a group of formula (c) or (d) defined above.

R₈ is preferably R₈ ' where R₈ ' is a direct bond or --CO--, --CH₂ CO--, --OCH₂ CO-- or --SO₂ --.

Preferably R₁₀ is R₁₀ ' where R₁₀ ' is hydrogen, methyl, chloro, bromo, C₁₋₂ alkoxy (max. 1 on a phenyl ring), or C₁₋₃ alkoxycarbonyl (max. 1 on a phenyl ring).

More preferably R₁₀ is R₁₀ " where R₁₀ " is hydrogen, methyl, chloro, bromo or methoxy (max. 1 on a phenyl ring).

Preferred compounds of formula I are of formula XX ##STR14## in which R, R₁ and R₂ are as defined above; either both groups R₂₀ are of formula (e) or both groups R₂₀ are of formula (f) ##STR15## where the starred atom is attached to the --NH group; R₁₃ is hydrogen, chloro, bromo, methyl, ethyl, C₁₋₂ alkoxy or C₁₋₄ alkoxycarbonyl;

R₁₄ is hydrogen, chloro, bromo or methyl;

R₁₅ is --CO--NH*--, --CO--O*-- or --SO₂ NH*--; the starred group being attached to the 2,2,6,6-tetraalkyl-piperidine group;

R₁₈ is 1,4-phenylene, unsubstituted or substituted by 1 or 2 groups selected from chloro, bromo, methyl, ethyl, methoxy and ethoxy; 4,4'-diphenylene, each phenylene group being unsubstituted or substituted by 1 or 2 groups selected from chloro, bromo, methyl, ethyl, methoxy and ethoxy; or unsubstituted 1,4- or 1,5-naphthalene.

Preferably, when R₁₄ is other than hydrogen it is para to R₁₃.

Preferably, R₁₅ is attached to the phenyl ring para to R₁₃ when R₁₄ is hydrogen and para to the azo moiety when R₁₄ is other than hydrogen.

Preferably, R₁₃ is chloro, methoxy or C₁₋₂ alkoxycarbonyl, more preferably chloro.

Preferably, R₁₄ is hydrogen or chloro.

Preferably, R₁₅ is --CO--NH-- or --SO₂ NH--.

Compounds of formula I or II can be prepared by reacting 1 mol of a compound of formula XXV

    D--R.sub.30                                                (XXV)

with n moles of a compound of formula XXVI or XXVII

Compounds of formula I or II can be prepared by reacting 1 mol of a compound of formula XXV

    D--R.sub.30                                                (XXV)

with n moles of a compound of formula XXVI or XXVII ##STR16## where one of R₃₀ and R₃₁ is --COCl or Cl and the other is --R₄ --H or one of R₃₀ and R₃₁ is --R₄ --Cl and the other is hydrogen; and

one of R₃₀ and R₃₂ is --COCl or Cl and the other is --R₈ --H or one of R₃₀ and R₃₁ is --R₈ --Cl and the other is hydrogen and the other symbols are as defined above.

Preferably where D is of the azo series, the above reaction is carried out at elevated temperatures, more preferably 80° to 150° C. Preferably where D is of the azo series the reaction is carried out in the presence of an inert solvent such as C₁₋₄ alkylbenzene, halobenzene or a high boiling liquid hydrocarbon.

Preferably where D is of the quinophthalone series, the above reaction is carried out at lower temperatures, more preferably 10°-40° C., most preferably room temperature (about 25°).

Preferably where D is of the perylene or perinone series, the reaction is carried out at elevated temperatures, preferably from 100° to 240° C.

Preferably where D is of the acetoacetylamine series the above reaction is carried out at temperatures from 20° to 100° C.

Preferably where D is of the isoindolinone dioxazine, phthalocyanine or pyrrolo-pyrrole series, the reaction is carried out at a temperature of 20° to 100° C.

Further, according to the invention there is provided a compound, for use in preparing a compound of formula I or formula II where D is of the azo series, of formula XXX or XXXI ##STR17## where R_(a) is the residue of a diazotisable amine or of a coupling component and the other symbols are as defined above. Preferably R_(a) is naphthyl or phenyl unsubstituted or substituted by 1 or 2 groups selected from Cl, Br, OH, NH₂, C₁₋₄ alkoxy, C₁₋₄ alkyl or C₁₋₃ alkoxycarbonyl.

The compounds according to the invention are suitable for pigmenting polymeric material such as polyethylene, polypropylene, polystyrene, polyvinylchloride, natural rubber and synthetic leather. The compounds according to the invention are also suitable for use in lacquers of various types, for example oil or water based paints. The compounds according to the invention are also suitable for pigmenting in the mass (either in solvent containing or solvent free systems) for example spin dyeing of viscose or cellulose acetate. The compounds according to the invention are also suitable for printing inks, for pigmenting paper and for applying to coatings of textiles.

The resulting pigmentations have excellent fastness properties to heat, light, weathering, chemicals, migration, bleeding, overlacquering and solvents. Further, the compounds according to the invention maintain their depth of colour and have good application properties, for example resistance to flocculation, resistance to crystallisation and fastness to dispersing.

Polymers to which pigments of the invention are applied are also stabilised against the effects of U.V. light by the pigments. The tensile strength of polymer containing a pigment according to the invention is significantly improved over that of virgin polymer.

The invention will now be illustrated by the following Examples in which all parts and percentages are by weight and all temperatures are in °C. unless indicated to the contrary.

EXAMPLE 1

61.9 Parts of 3-amino-4-chloro-benzoic acid-2',2',6',6'-tetramethyl-piperidinylamide are stirred for 1 hour in 100 parts of water and 105 parts of glacial acetic acid at room temperature. This is then reacted with 75 parts of conc. HCl and stirred a further hour. The mixture is then cooled to 0°-5° by adding 100 parts of ice and immersing the reaction vessel in an ice/water bath. 51 parts by volume of 4N aqueous sodium nitrite solution is added slowly over 15-20 minutes and the mixture is stirred for a further hour, whilst maintaining the temperature below 5°. The resulting diazonium chloride solution is then clear filtered.

25.6 Parts of barbituric acid are dissolved in 100 parts of water and 20 parts by volume of a 30% aqueous NaOH solution which is then precipitated out again in a mixture of 100 parts of water and 21 parts of glacial acetic acid. The suspension is cooled to 0° to 5° and, whilst stirring is added over 25 minutes to the diazonium solution which is also at that temperature. The resultant yellow suspension is stirred for 3 hours whilst further cooling, then for one hour at room temperature and then for a further hour at 80°-85°, filtered and the precipitate is washed with salt and acid-free water, dried at 80° and milled. A pigment of the formula 1a ##STR18## results that colours polypropylene a yellow tone and the resulting pigmentations have good fastness properties. The coloured polypropylene can also be worked into fibres having good tensile strength.

EXAMPLE 2

25.3 Parts of 4,4'-diamino-3,3'-dichloro-1,1'diphenyl are stirred for 1 hour in 60 parts of water and 60 parts of concentrated HCl at room temperature and this is then cooled to 0° to 5° by adding 100 parts of ice and immersing the reaction vessel in an ice cold bath. The solution that forms is added, whilst stirring, to 51 parts by volume of 4N aqueous sodium nitrite over 15-20 minutes and this is stirred for a further hour at 0° to 5°. The resulting diazonium solution is then clear filtered.

57.8 Parts of 1-(2',2',6',6'-tetramethylpiperidinyl)-2-hydroxy-4-methyl-5-cyanopyrid-6-one, are dissolved in 200 parts by volume water and 25 parts by volume of a 30% solution of aqueous NaOH and by the slow addition of a mixture of 100 parts of ice, 100 parts by volume of water and 25 parts by volume of glacial acetic acid, the pyridone product precipitates out again. The suspension that results is then slowly added, over 20-30 minutes at 0° to 5° whilst stirring, to the above-mentioned diazonium solution.

The resulting red suspension is of the pigment of formula 2a ##STR19##

The suspension is stirred for a further 3 hours at 0° to 5° and for a further hour at 80° to 85°. The suspension is then filtered, the precipitate is washed with salt and acid-free water and is then dried under vacuum at 80°.

83.6 Parts of the pigment of formula 2a results, that colours polypropylene a red tone and the resulting pigmentations have good fastness properties. The polymer can be worked into fibres having good tensile strength.

EXAMPLE 3

1.2 Parts of sodium metal are dissolved in 80 parts of methanol. The solution is cooled to 20° C. and 12.8 parts of phthalodinitrile are added. The suspension that results is stirred for 11/2 hours at 20° to 25°. 23.5 parts of 4-cyanoacetylamino-2,2,5,6-tetramethyl piperidine are added and the mixture is stirred at room temperature for 16 hours. 3 parts glacial acetic acid are added and a golden yellow intermediate product precipitates out which is washed with methanol and water and then dried under vacuum at 60°.

17.5 Parts of the so formed intermediate product are stirred into 100 parts of dimethylformamide and are then reacted with 6.4 parts of barbituric acid. A yellow pigment is formed very quickly. After stirring for 16 hours at 20°-25°, the mixture is heated for a further hour to 80° and then is reacted with 3 parts of glacial acetic acid. The resulting pigment is of formula 3a ##STR20## and at 20° can be filtered off, washed with dimethylformamide and cold water and dried.

After milling, the pigment can be added to plastics materials and to lacquers to colour them yellow and produce pigmentations having good fastness properties.

EXAMPLE 4

4.8 Parts of zinc acetate dihydrate, 6.5 parts of perilene-3,4,9,10-tetracarboxylic acid dianhydride and 14.3 parts of 3-aminobenzene sulphonic acid-2',2',6',6'-tetramethylpiperidinylamide are heated to 220° in 120 parts of quinoline under a weak nitrogen atmosphere and left at this temperature for 5 hours. After this time, a sample, boiled in dilute NaOH solution, shows no free perilene tetracarboxylic acid present.

After cooling to 100°, the mixture is filtered and the residue is washed in quinoline, methanol and water. The resulting damp presscake is heated to 95° in 100 parts of 2% aqueous sodium hydroxide, after which it is filtered off and then washed, dried and milled. 9 Parts of the pigment of formula 4a ##STR21## result, which pigment is a red bordeaux colour and has good properties in plastics material.

EXAMPLE 5

65.4 Parts of pyromellitic acid dianhydride and 61 parts of 3-hydroxy-2-methyl-quinoline-4-carboxylic acid are heated under reflux at 205° in 1000 parts of nitrobenzene for 1 hour, distilling off the water produced by the reaction. The mixture is held at this temperature for 31/2 hours. The mixture is then cooled to 10° and after stirring at this temperature for 1 hour, is filtered and the product is washed in toluene and ethanol. 93 parts of a dark brown quinophthalone intermediate result.

90 Parts of this quinophthalone intermediate are stirred homogenously with 900 parts of 1-methyl-2-pyrrolidinone for 1 hour. When the mixture is at about 25°, 42 parts of 4-amino-2,2,6,6-tetramethyl-piperidine are added. The temperature rises to about 35°. After the exothermic reaction has terminated, the mixture is heated to 120° over 1 hour and held for 2 hours at this temperature. The mixture is then refluxed for 15 hours, distilling off the water produced by the reaction, after which it is cooled to room temperature, filtered, washed with a little 1-methyl-2-pyrrolidinone and alcohol and then dried. 81 parts of a bronze pigment of formula 5a ##STR22## result, that can be used to colour polypropylene brown and such pigmentations have good fastness properties.

EXAMPLE 6

33.45 Parts of a product derived from the coupling of 2 mols of diazotised 3-amino-4-chlorobenzoic acid and 1 mol of 1,4-bis-acetoacetylamino-2,5-dimethylbenzene are stirred in 300 parts by volume of ortho-dichlorobenzene and 1 part by volume of dimethylformamide. This is then heated to 100° and slowly reacted with 10 parts of thionyl chloride and is then stirred for 2 hours at 100° whereby the suspension thickens. Any excess of thionyl chloride, together with about 20 parts by volume of ortho-dichlorobenzene is distilled off at 70°-80° under vacuum (20-30 mm of Hg). To the remaining mixture, a solution of 15.5 parts of 4-amino-2,2,6,6-tetramethylpiperidine in 80 parts by volume of ortho-dichlorobenzene is added and the mixture is stirred for 2 hours at 120°, followed by a further 2 hours at 150°, after which the suspension is cooled to 80°-100°. The resulting reddish yellow suspension is then filtered, washed with orthochlorobenzene (at 80°-100°) until the filtrate is colourless. After cooling, the orth-dichlorobenzene is separated from the filtrate by the addition of methanol, and this is then washed out of the methanol with water and the resulting pigment is dried.

The resulting pigment is of formula 6a ##STR23## and colours polypropylene a reddish-yellow tone.

EXAMPLE 7

Example 1 is repeated using, instead of 25.6 parts of barbituric acid, 29.0 parts of 1,4-bis-acetoacetylamino-2-methylbenzene to form the pigment of formula 7a ##STR24##

The pigment of formula 7a colours polypropylene a yellow tone and produces pigmentations with good fastness properties.

EXAMPLE 8

Example 7 is repeated using (instead of 61.9 parts of 3-amino-4-chlorobenzoic acid-2',2',6',6'-tetramethylpiperidinylamide) 76.0 parts of 4-amino-2,5-dichlorobenzene sulphonic acid-2',2',6',6'-tetramethyl piperidinylamide. The resulting pigment is of formula 8a ##STR25## which colours polypropylene a yellow tone and produces pigmentations with good fastness properties. The polypropylene can also be worked into fibres that have a good tensile strength.

EXAMPLE 9

(i) 38.0 Parts of 4-amino-2,5-dichlorobenzene sulphonic acid-2',2',-6',6'-tetramethylpiperidinylamide in 50 parts of water and 50 parts of glacial acetic acid are diazotised according to the method of Example 1.

To this product 18.8 parts of 2-hydroxy-3-naphthalene carboxylic acid in 10 parts by volume of water and 15 parts by volume of a 30% aqueous NaOH solution are added and coupled according to the method of Example 1. The compound of formula 9a ##STR26## results.

(ii) 57.9 Parts of the compound of formula 9a are then stirred into 300 parts by volume of 1,2-dichlorobenzene. In order to remove resultant water, the mixture is distilled at 70°-80° under vacuum and about 30 parts by volume of 1,2-dichlorobenzene and water are removed. The mixture is then cooled to 60° and 1 part by volume dimethyl formamide and 10.2 parts by volume of thionyl chloride are added and are stirred for 3 hours at 100°-110°, whereby SO₂ and HCl are given off in forming the resulting acid chloride of the pigment of formula 9a.

Then the excess thionyl chloride is distilled off at 70°-80° under vacuum together with 30 parts by volume 1,2-dichlorobenzene.

A solution of 8.9 parts of 1,4-diamino-2,5-dichlorobenzene(the condensation amine) dissolved in 150 parts by volume of 1,2-dichlorobenzene at 100° is added to the acid chloride suspension. The resulting red pigment suspension is stirred for 2 hours at 120° and then for a further 2 hours at 150°. It is then filtered at 100°, washed with 400 parts by volume of 1,2-dichlorobenzene at 100°, cooled to room temperature and then washed with 500 parts by volume of methanol and 500 parts by volume of water. The filter cake is dried and then milled. 59.8 parts of a red pigment of formula 9b ##STR27## results, that is good for pigmenting polypropylene fibres in the mass and the resulting fibres have good tensile strength.

EXAMPLE 10

Example 9 is repeated using 31 parts of 3-amino-4-chlorobenzoic acid-2',2',6',6'-tetramethyl piperidinylamide instead of 38 parts of 4-amino-2,5-dichlorobenzene sulphonic acid-2',2',6',6-tetramethylpiperidinylamide.

56.7 Parts of the pigment of the formula 10a ##STR28## result, that colours polypropylene red by pigmentation in the mass and produces fibres with good tensile strength.

(ii) The pigment of formula 10a can also be prepared by a method analogous with that of Example 1 using 31 parts of 3-amino-4-chlorobenzoic acid-2',2',6',6'-tetramethylpiperidinyl amide (instead of 61.9 parts of 3-amino-4-chlorobenzoic acid-2',2',6',6'-tetramethylpiperidinylamide) and 25.9 parts of 1,4-bis-(2'-hydroxy-3-naphthoylamino)-2,5-dichlorobenzene (instead of 25.6 parts of barbituric acid). Twice as much water is however used in the step of reacting the diazonium chloride solution with the coupling component and twice as much water is used when adding the glacial acetic acid.

(iii) The pigment of formula 10a can also be made by a method analogous with that of Example 9(ii) by coupling 2 moles of diazotised 3-amino-4-chlorobenzoic acid with 1 mol of 1,4-bis(2'-hydroxy-3'-naphthoylamino)-2,5-dichlorobenzene forming the acid chloride with thionyl chloride and condensing this acid chloride with 2,2,6,6-tetramethyl-4-aminopiperidine.

EXAMPLES 11 to 14

Compounds of the formula 4a ##STR29## in which Q is as given in Table 1 below, can be formed by a method analogous to that of Example 4 from appropriate reactants.

                                      TABLE 1                                      __________________________________________________________________________     Ex. No.                                                                             Q                        Colour in Polypropylene                          __________________________________________________________________________     11                                                                                   ##STR30##               Red                                              12                                                                                   ##STR31##               Red                                              13                                                                                   ##STR32##               Red-brown                                        14                                                                                   ##STR33##               red-violet                                       __________________________________________________________________________

EXAMPLES 15 to 46

Compounds of the formula ##STR34## in which the symbols are as defined in Table 2 below can be prepared by a method analogous to that of Example 7 from appropriate reagents.

                                      TABLE 2                                      __________________________________________________________________________                                 Colour in       pos.                               Ex.                         polypropy-      of                                 No.                                                                               R     R.sub.13                                                                              R.sub.14                                                                          R.sub.18 lene     R.sub.15                                                                              R.sub.15                           __________________________________________________________________________     15 H     Cl     H  1,4-phenylene                                                                           yellow   --CONH--                                                                              4                                  16 H     Cl     H  2-chloro-1,4-                                                                           "        "      4                                                     phenylene                                                   17 H     Cl     H  2,5-dichloro-1,4-                                                                       "        "      4                                                     phenylene                                                   18 H     Cl     H  2-methoxy-1,4-                                                                          "        "      4                                                     phenylene                                                   19 H     Cl     H  2,5-dimethoxy-1,4-                                                                      reddish- "      4                                                     phenylene                                                                               yellow                                             20 H     Cl     H  2-chloro-5-methyl-                                                                      yellow   "      4                                                     1,4-phenylene                                               21 H     Cl     H  3,3'-dimethyl-4,4'                                                                      yellow   "      4                                                     diphenylene                                                 22 H     CH.sub.3                                                                              H  2,5-dimethyl-1,4-                                                                       "        "      4                                                     phenylene                                                   23 H     --OCH.sub.3                                                                           H  "        "        "      4                                  24 H     --COOCH.sub.3                                                                         H  1,4-phenylene                                                                           "        "      4                                  25 H     "      H  2,5-dimethyl-1,4-                                                                       "        "      4                                                     phenylene                                                   26 H     "      H  2-methyl-5-chloro-                                                                      "        "      4                                                     1,4-phenylene                                               27 H     --COOC.sub.2 H.sub.5                                                                  H  2,5-dimethyl-1,4-                                                                       "        "      4                                                     phenylene                                                   28 --COCH.sub.3                                                                         Cl     H  1,4-phenylene                                                                           "        "      4                                  29 "     Cl     H  2,5-dimethyl-1,4-                                                                       "        "      4                                                     phenylene                                                   30 "     Cl     H  2-chloro-5-methyl-                                                                      "        "      4                                                     1,4-phenylene                                               31 "     --COOCH.sub.3                                                                         H  2,5-dimethyl-1,4-                                                                       "        "      4                                                     phenylene                                                   32 "     "      H  2-chloro-5-methyl-                                                                      "        "      4                                                     1,4-phenylene                                               33 "     "      H  1,4-phenylene                                                                           "        "      4                                  34 H     Cl     H  1,4-phenylene                                                                           reddish- --SO.sub.2 NH--                                                                       4                                                              yellow                                             35 H     Cl     H  2,5-dimethyl-1,4-                                                                       "        "      4                                                     phenylene                                                   36 H     Cl     H  2-chloro-5-methyl-                                                                      "        "      4                                                     1,4-phenylene                                               37 H     Cl     4-Cl        "        "      3                                  38 H     Cl     4-Cl                                                                              1,4-phenylene                                                                           "        "      3                                  39 H     Cl     4-Cl                                                                              2-chloro-1,4-                                                                           "        "      3                                                     phenylene                                                   40 H     Cl     4-Cl                                                                              2,5-dichloro-1,4-                                                                       "        "      3                                                     phenylene                                                   41 H     Cl     4-Cl                                                                              2-methoxy-1,4-                                                                          "        "      3                                                     phenylene                                                   42 H     Cl     4-Cl                                                                              2,5-dimethoxy-1,4-                                                                      reddish- "      3                                                     phenylene                                                                               yellow                                             43 H     Cl     4-Cl                                                                              2,5-dimethyl-1,4-                                                                       yellow   "      3                                                     phenylene                                                   44 H     Cl     4-Cl                                                                              3,3'-dimethyl-4,4'-                                                                     "        "      3                                                     diphenylene                                                 45 H     Cl     4-Cl                                                                              1,5-naphthylene                                                                         "        "      3                                  46 H     Cl     4-Cl                                                                              1,4-naphthylene                                                                         "        "      3                                  __________________________________________________________________________

EXAMPLES 47 to 84

The pigments of Examples 47 to 75 defined in Table 3 can be prepared according to the method of Example 9 and the pigments of Examples 75 to 84 (defined in Table 4) can be made analogously to the method of Example 10 from appropriate reactants.

                                      TABLE 3                                      __________________________________________________________________________                                     Colour in                                      Ex.             Coupling                                                                              Condensation                                                                            polypro-                                       No.                                                                               Diazo Component                                                                             Component                                                                             amine    lene                                           __________________________________________________________________________     47 3-amino-4-chloro-benzene                                                                    2-hydroxy-                                                                            1,4-diamino                                                                             yellowish-                                        sulfonic acid 2',2',6'-                                                                     3-naphthene                                                                           benzene  red                                               6'-tetramethylpiperidi-                                                                     carboxylic                                                        nyl-amide    acid                                                           48 "            "      1,4-diamino-2-                                                                          red                                                                   chlorobenzene                                           49 "            "      1,4-diamino-2-                                                                 chloro-5-                                                                               red                                                                   methylbenzene                                           50 "            "      1,4-diamino-2-                                                                          reddish-                                                              methoxybenzene                                                                          brown                                          51 "            "      3,3'-dichloro-                                                                          red                                                                   benzidine                                               52 "            "      1,4-diamino-2,5-                                                                        "                                                                     dichlorobenzene                                         53 4-amino-2,5-dichloro-                                                                       "      1,4-diamino                                                                             yellowish-                                        benzene sulfonic acid                                                                              benzene  red                                               2',2',6',6'-tetra-                                                             methylpiperidinylamide                                                      54 "            "      1,4-diamino                                                                             blueish-                                                              2-chlorobenzene                                                                         red                                            55 "            "      3,3'-dichloro-                                                                          red                                                                   benzidine                                               56 "            "      1,5-diamino-                                                                            brown                                                                 naphthalene                                             57 "            "      1,4-diamino-2-                                                                          red                                                                   methyl-5-chloro-                                                               benzene                                                 58 4-amino-2,6-dichloro-                                                                       "      1,4-diamino-                                                                            "                                                 benzene sulfonic acid-                                                                             benzene                                                    2',2',6',6'-tetra-                                                             methylpiperidinylamide                                                      59 4-amino-2,6-dichloro-                                                                       2-hydroxy-                                                                            1,4-diamino-2,5-                                                                        red                                               benzene sulfonic acid-                                                                      3-naphthene                                                                           dichlorobenzene                                            2',2',6',6'-tetra-                                                                          carboxylic                                                        methylpiperidinylamide                                                                      acid                                                           60 4-amino-2,6-dichloro-                                                                       2-hydroxy-                                                                            3,3'-dichloro-                                                                          red                                               benzene sulfonic acid                                                                       3-naphthoic                                                                           benzidine                                                  2',2',6,6'-tetramethyl-                                                                     acid                                                              piperidinylamide                                                            61 "            "      1,5-diamino-                                                                            brown                                                                 naphthalene                                             62 2-amino-4,5-dichloro-                                                                       "      1,4-diamino                                                                             red                                               benzene sulfonic acid                                                                              benzene                                                    2',2',6,6'-tetramethyl-                                                        piperidinylamide                                                            63 "            "      1,4-diamino-2,5-                                                                        "                                                                     dichlorobenzene                                         64 "            "      3,3'-dichloro-                                                                          "                                                                     benzidine                                               65 "            "      1,5-diamino-                                                                            brown                                                                 naphthalene                                             66 3-amino-4-chloro-                                                                           "      1,4-diamino-                                                                            yellowish-                                        benzoic acid-2',2',-                                                                               benzene  red                                               6',6'-tetramethyl-                                                             piperidinylamide                                                            67 "            "      1,4-diamino-2-                                                                          red                                                                   chlorobenzene                                           68 "            "      1,4-diamino-2-                                                                          red                                                                   chloro-5-methyl                                                                benzene                                                 69 "            "      1,4-diamino-2-                                                                          red-brown                                                             methoxybenzene                                          70 "            "      3,3'-dichloro-                                                                          red                                                                   benzene                                                 71 3-amino-4-carbomethoxy                                                                      "      1,4-diamino-                                                                            yellowish-                                        benzoic acid 2',2',6'-                                                                             benzene  red                                               6'-tetramethylpiperi-                                                          dinylamide                                                                  72 3-amino-4-carboxymethoxy                                                                    2-hydroxy-                                                                            1,4-diamino-2-                                                                          blueish-                                          benzoic acid 2',2',6'-                                                                      3-naphthene                                                       6'-tetramethylpiperi-                                                                       carboxylic                                                        dinylamide   acid   chlorobenzene                                                                           red                                            73 "            "      1,4-diamino-2,5-                                                                        red                                                                   dichlorobenzene                                         74 "            "      3,3'-dichloro-                                                                          red                                                                   benzidine                                               75 "            "      1,5-diamino-                                                                            brown                                                                 naphthalene                                             __________________________________________________________________________

                                      TABLE 4                                      __________________________________________________________________________     Ex.                                                                               Diazo Component                                                                            Coupling Component                                                                            Nuance                                           __________________________________________________________________________     76 3-amino-4-chlorobenzoic                                                                    2-hydroxy-3-naphthoic acid-                                                                   red                                                 acid-2',2',6',6'-tetra-                                                                    (4'-benzoylamino)-phenyl-                                          methylpiperidinylamide                                                                     amide                                                           77 "           5-(2'-hydroxy-3-naphthoyl                                                                     brown                                                           amino)-benzimidazolone                                          78 "           5-acetoacetylaminobenzimida-                                                                  yellow                                                          zolone                                                          79 3-amino-4-methoxy-                                                                         2-hydroxy-3-naphthoic acid                                                                    red                                                 carbonylbenzoic acid                                                                       (4'-benzoylamino)-                                                 2',2',6',6'-tetra-                                                                         phenylamide                                                        methylpiperidinylamide                                                      80 "           5-(2'-hydroxy-3'-naphthoyl-                                                                   brown                                                           amino)-benzimidazolone                                          81 "           5-acetoacetylamino-benzimi-                                                                   yellow                                                          dazolone                                                        82 4-aminobenzoic acid                                                                        2-hydroxy-3-napthoic acid-                                                                    yellowish-                                          2',2',6',6'-tetramethyl-                                                                   2'-methoxy-phenylamide                                             piperidylamide                                                              83 "           2-hydroxy-3-naphthoic acid                                                                    scarlet                                                         2'-ethoxyphenylamide                                            84 "           2-hydroxy-3-naphthoic acid                                                                    red                                                             phenylamide                                                     __________________________________________________________________________

EXAMPLE 85

(a) 3-aminobenzene sulphonic acid-2',2',6',6'-tetramethylpiperidinylamide (of Example 4) can be prepared by sulphochlorination and amidation of nitrobenzene with 4-amino-2,2,6,6-tetraalkylpiperidine followed by reduction with a sulphide (e.g. NaS). A white powder having a melting point of 244°-245° results.

(b) 4-(4'-chloro-3'-aminobenzoyl-)amino-2,2,6,6-tetramethylpiperidine can be prepared as follows.

A solution of 55.2 parts of 3-nitro-4-chlorobenzoyl chloride in 200 parts by volume of toluene is added dropwise to well stirred solution (at room temperature) of 100 parts by volume of toluene, 41 parts of 2,2,6,6-tetramethyl-4-aminopiperidine, 1 part of tetrabutyl ammonium bromide and 120 parts by volume of a 30% aqueous sodium hydroxide solution.

The mixture is stirred overnight and the resulting precipitate is filtered off. After washing with toluene and n-hexane, the filtrate is vacuum dried and in order to remove any organic salts present is added to 1000 parts of water. After a further filtration step and drying, 74 parts of 4-(4'-chloro-3'-nitrobenzoyl)amino 2,2,6,6-tetramethylpiperidine having a melting point of 166°-168° result.

In order to convert this to the amine, 68 parts of the nitro compound are added to a mixture of 600 parts by volume of 94% ethanol, 80 parts of iron powder and 16 parts of 30% HCl solution at boiling. After boiling for a number of hours, reduction is terminated. After adding 14 parts of sodium carbonate, the resulting iron oxide precipitate is filtered off. After concentrating by boiling under vacuum, 4-(3'-amino,4'-chlorobenzoyl)amino-2,2,6,6-tetramethylpiperidine results.

(c) 4-(3'-amino-4-chlorobenzoyl)amino-2,2,6,6-tetramethyl-1-acetylpiperidine can be prepared as follows:

68 Parts of 4-(3'-nitro-4'-chlorobenzoyl)-amino-2,2,6,6-tetramethylpiperidine are added to 250 parts of acetic anhydride. After the addition of 21 parts of triethylamine, the suspension is stirred for 16 hours at toom temperature and then for 3 hours at 100°-110°. In order to complete precipitation of the acetyl derivative, 1500 parts by volume of cold water are added and stirred at room temperature until all the excess acetic anhydride is destroyed. The precipitate is then filtered, washed neutral with water and dried. 72 parts of 4-(3'-nitro-4'-chlorobenzoyl)-amino-1-acetyl-2,2,6,6-tetramethyl-piperidine having a melting point of 198°-200° results.

Reduction may then be carried out as described under (b) above as for the N-unsubstituted tetraalkylpiperidinyl compound with iron in an aqueous alcohol system.

A good yield of 4-(3'-amino-4'-chlorobenzoyl)amino-1-acetyl-2,2,6,6-tetramethylpiperidine having a melting point of 232°-234° result.

(d) 4-cyanoacetylamino-2,2,6,6-tetramethylpiperidine (in Example 3) can be produced by reacting 4-amino-2,2,6,6-tetramethylpiperidine with the ethyl ester of cyanoacetic acid in the absence of solvent at 90°.

APPLICATION EXAMPLE A

0.05 Parts of the compound of Example 1 are homogenised in a mixing roller mill at 150°-160° for about 8 minutes, with 2 parts of dibutyl-tin-bis-thioglycollic acid hexyl ester and 50 parts of a mixture consisting of 65% polyvinylchloride and 35% diethylhexylphthalate.

The polymer is rolled into a sheet and then is glossed in a double roller calender. The resultant transparent sheet has good light fastness properties.

APPLICATION EXAMPLE B

Four parts of the compound of Example 1 are added to 96 parts of a mixture of:

50 parts of a 60% solution of coco aldehyde-melamine resin of 32% of fat content in xylene,

30 parts of a 50% melamine resin solution in butanol,

10 parts of ethylene glycol monoethylether and

10 parts of xylene,

and the mixture ground for 24 hours in a ball mill. The dispersion obtained is sprayed on an aluminium sheet, the spray coating allowed to dry in the air for 30 minutes and then stoved for 30 minutes at 120°. A yellow film with good light and weathering fastness is obtained.

APPLICATION EXAMPLE C

The 990 parts of a commercially available U.V. stabilised polypropylene spin fibre type, 10 parts of the compound of formula 6a are added by a dry colouring method over 10 minutes, after which the polymer is extruded. Fibres that have a fibre of 15 d tex are obtained.

Tensile strength comparisons are then carried out on fibres that have been exposed for 200, 400, 600 and 800 hours (in a weatherometer). Fibres that have been exposed for 400 hours have a tensile strength of 57% of the value of unexposed fibres.

As a comparison polypropylene is coloured with the pigment of Example 2 of DAS 1,150,165 under the same conditions and after 400 hours the tensile strength of the fibres is only 20% of the value of the unexposed fibres.

Application Examples A to C can be repeated using an appropriate amount of an other compound of Examples 1 to 6 and 8 to 84. 

What is claimed is:
 1. A polymeric composition comprising a polymeric material pigmented with a pigment of formula I or II ##STR35## in which R is hydrogen, C₁₋₈ alkyl, C₃₋₁₀ alkenyl, phenyl, phenyl-C₁₋₄ alkyl or --COR_(5a) where R_(5a) is hydrogen, --C(R_(10a))═CH₂, C₁₋₆ alkyl, phenyl, --COOC₁₋₄ alkyl or --NR₂₁ R₂₂, where R_(10a) is hydrogen or C₁₋₄ alkyl; R₂₁ is hydrogen, C₁₋₁₂ alkyl, C₅₋₆ cycloalkyl, phenyl, phenylC₁₋₄ alkyl or C₁₋₁₂ alkylphenyl and R₂₂ is C₁₋₁₂ alkyl or hydrogen;each R₁ independently is --CH₃ or --CH₂ (C₁₋₄ alkyl) or both groups R₁ form a group --(CH₂)_(5--;) each R₂ independently is --CH₃ or --CH₂ (C₁₋₄ alkyl) or both groups R₂ form a group --(CH₂)₅ --; R₄ is a direct bond or a bridging group and R₅ is hydrogen or C₁₋₄ alkyl, or R₄ and R₅ together with the carbon atom to which they are attached form an isocyclic or heterocyclic bridging group; R₆ is --NH₂, mono or di--C₁₋₄ alkylamino, C₁₋₂ alkylcarbonylamino, benzoylamino, hydrogen, OH or --CO--C₁₋₄ alkyl or --CO--C₁₋₄ alkoxy and R₇ is hydrogen or C₁₋₄ alkyl, or R₆ or R₇ together with the carbon atom to which they are attached form an isocyclic or heterocyclic ring; R₈ is a direct bond or a bridging group; D is a residue of a pigment; and n is an integer from 1 to 4 inclusive.
 2. A composition according to claim 1, in which D is a pigment residue of the azo, perinone, perylene, quinophthalone, isoindolinone, dioxazine, acetoacetylamine, phthalocyanine or pyrrolo-pyrrole series.
 3. A composition according to claim 1, in which D is D' where D' is a group of formula III to VIII when monovalent ##STR36## or D' is a group of formula IX to XV, when divalent ##STR37## or D' is a group of the formula XVI, when trivalent ##STR38## or D' is a group of the formula XVII, when tetravalent ##STR39## in which D₁ is 1,3- or 1,4-phenylene, unsubstituted or mono or di-substituted by substituents selected from the group consisting of chloro, bromo, C₁₋₂ alkyl, C₁₋₂ alkoxy, carboxy or C₁₋₄ alkoxycarbonyl; or 1,4, -1,5- or 1,8-anthraquinone, unsubstituted or mono or disubstituted by substituents selected from the group consisting of chloro, bromo, hydroxy, C₁₋₃ alkoxy or acylamino;D₂ is phenyl, unsubstituted or substituted by one to three substituents, selected by the group consisting of chloro (max. 2), bromo (max. 2), C₁₋₂ alkoxy (max 2), C₁₋₄ alkoxy carbonyl (max 2) and acylamino (max 1); D₃ is a 4,4'-diphenylene group, unsubstituted or substituted by one to four substituents selected from chloro, bromo, C₁₋₂ alkyl and C₁₋₂ alkoxy or is a group of formula ##STR40## where the starred atoms are attached to the azo in a group of formula VIII K₁ is a group of any one of formula K_(1a) to K_(1f) ##STR41## where the starred atom is attached to the azo group of IV or X; and R₁₆ is --O-- or --NH--; K₂ is a group of any one of formula K_(2a) to K_(2c) ##STR42## K₃ is a group of any one of formula K_(3a) to K_(3g) ##STR43## in which R₁₀ is hydrogen, chloro, bromo, C₁₋₃ alkoxycarbonyl, C₁₋₂ alkyl, C₁₋₂ alkoxy or nitro; R_(g) is 1,4-phenylene, unsubstituted or substituted by one or two groups selected from chloro, bromo, methyl or C₁₋₂ alkoxy; -4,4'-diphenylene; 1,4- or 1,5-naphthylene or a group of the formula ##STR44## where A is --CH₂ --, --NHCO--, --NHCONH--, --NH--CO--CO--NH-- or ##STR45## R₁₁ is methyl, --COOH or --COOC₁₋₄ alkyl; and R₁₇ is --OH, methyl or unsubstituted phenyl.
 4. A composition according to claim 1 wherein the pigment is of the formula XX ##STR46## in which R, R₁ and R₂ are as defined in claim 2; either both groups R₂₀ are of formula (e) or both groups R₂₀ are of formula (f) ##STR47## where the starred atom is attached to the --NH group; R₁₃ is hydrogen, chloro, bromo, methyl, ethyl, C₁₋₂ alkoxy or C₁₋₄ alkoxycarbonyl;R₁₄ is hydrogen, chloro, bromo or methyl; R₁₅ is --CO--NH*--, --CO--O*-- or --SO₂ NH*--; the starred group being attached to the 2,2,6,6-tetraalkyl-piperidine group. R₁₈ is 1,4-phenylene, unsubstituted or substituted by 1 or 2 groups selected from chloro, bromo, methyl, ethyl, methoxy and ethoxy; 4,4'-diphenylene, each phenylene group being unsubstituted or substituted by 1 or 2 groups selected from chloro, bromo, methyl, ethyl, methoxy and ethoxy; or unsubstituted 1,4- or 1,5-naphthalene.
 5. A polymeric composition according to claim 1 in which the polymeric material is polypropylene or polyethylene.
 6. A composition according to claim 1 wherein,when R₄ is a bridging group, it is *--NHCO--, *--NHSO₂ -, *--NH--CO--O--, *--NH--COCH₂ O--, *--NHCOCO--, --NHCOCONH--, *--NHCOCOO--, *--OCO--, *--OSO₂ --, *--OCOCO--, --OCO--CO--O--, *--OCONH-- or *--OCOCONH--, where the starred atom is attached to the piperidine ring; when R₄ and R₅ together with the carbon atom to which they are attached form a heterocyclic or isocyclic ring, this ring is a group of formula (a) or (b) ##STR48## in which the starred atom is attached to D; when R₆ and R₇ together with the carbon atom to which they are attached form a heterocyclic or isocyclic ring, this ring is a group of formula (c) or (d) ##STR49## where R₁₂ is hydrogen, C₁₋₄ alkyl or C₁₋₄ alkoxycarbonyl-C₁₋₃ alkyl; and when R₈ is a bridging group, it is --CO--, --CH₂ *CO--, --OCH₂ *CO-- or --SO₂ --, where the starred atom is attached to the piperidine ring.
 7. A composition according to claim 2 wherein,when R₄ is a bridging group, it is *--NHCO--, *--NHSO₂ --, *--NH--CO--O--, *--NH--COCH₂ O--, *--NHCOCO--, --NHCOCONH--, *--NHCOCOO--, *--OCO--, *--OSO₂ --, *--OCOCO--, --OCO--CO--O--, *--OCONH-- or *--OCOCONH--, where the starred atom is attached to the piperidine ring. when R₄ and R₅ together with the carbon atom to which they are attached form a heterocyclic or isocyclic ring, this ring is a group of formula (a) or (b) ##STR50## in which the starred atom is attached to D; when R₆ and R₇ together with the carbon atom to which they are attached form a heterocyclic or isocyclic ring, this ring is a group of formula (c) or (d) ##STR51## where R₁₂ is hydrogen, C₁₋₄ alkyl or C₁₋₄ alkoxycarbonyl-C₁₋₃ alkyl; and when R₈ is a bridging group, it is --CO--, --CH₂ *CO--, --OCH₂ *CO-- or --SO₂ --, where the starred atom is attached to the piperidine ring.
 8. A composition according to claim 3 wherein,when R₄ is a bridging group, it is *--NHCO--, *--NHSO₂ --, *--NH--CO--O--, *--NH--COCH₂ O--, *--NHCOCO--, --NHCOCONH--, *--NHCOCOO--, *--OCO--, *--OSO₂ --, *--OCOCO--, --OCO--CO--O--, *--OCONH-- or *--OCOCONH--, where the starred atom is attached to the piperidine ring. when R₄ and R₅ together with the carbon atom to which they are attached form a heterocyclic or isocyclic ring, this ring is a group of formula (a) or (b) ##STR52## in which the starred atom is attached to D; when R₆ and R₇ together with the carbon atom to which they are attached form a heterocyclic or isocyclic ring, this ring is a group of formula (c) or (d) ##STR53## where R₁₂ is hydrogen, C₁₋₄ alkyl or C₁₋₄ alkoxycarbonyl-C₁₋₃ alkyl; and when R₈ is a bridging group, it is --CO--, --CH₂ *CO--, --OCH₂ *CO-- or --SO₂ --, where the starred atom is attached to the piperidine ring.
 9. A composition according to claim 3 wherein, in any acylamino substituent on D₁ or D₂, the acyl group is --COC₁₋₄ alkyl or --COC₁₋₄ alkoxy.
 10. A composition according to claim 4 wherein each R₁ and each R₂ is methyl and R is R' where R' is hydrogen, methyl, formyl, C₁₋₄ alkylcarbonyl or --CO--CO--OC₁₋₄ alkyl.
 11. A composition according to claim 6 whereinR is R' where R' is hydrogen, methyl, formyl, C₁₋₄ alkylcarbonyl or --CO--CO--OC₁₋₄ alkyl; each R₁ and R₂ is methyl; R₄ is R'₄ and R₅ is R'₅ where either R'₄ is a direct bond, --NH--CO-- or --NH--CO--CH₂ --O-- and R'₅ is hydrogen or R'₄ and R'₅ together with the carbon atom to which they are attached form a group of formula (a) or (b); R₆ is R'₆ and R₇ is R'₇ where either R'₆ is --NH₂, mono- or di- C₁₋₄ alkylamino, C₁₋₂ alkylcarbonylamino or benzoylamino and R'₇ is hydrogen or R'₆ and R'₇ together with the carbon atom to which they are attached form a group of formula (c) or (d); and R₈ is R'₈ where R'₈ is a direct bond or --CO--, --CH₂ CO--, --OCH₂ CO-- or --SO₂₋₋.
 12. A composition according to claim 7 wherein,R is R' where R' is hydrogen, methyl, formyl, C₁₋₄ alkylcarbonyl or --CO--CO--OC₁₋₄ alkyl; each R₁ and R₂ is methyl; R₄ is R'₄ and R₅ is R'₅ where either R'₄ is a direct bond, --NH--CO-- or --NH--CO--CH₂ --O-- and R'₅ is hydrogen or R'₄ and R'₅ together with the carbon atom to which they are attached form a group of formula (a) or (b); R₆ is R'₆ and R₇ is R'₇ where either R'₆ is --NH₂, mono- or di- C₁₋₄ alkylamino, C₁₋₂ alkylcarbonylamino or benzoylamino and R'₇ is hydrogen or R'₆ and R'₇ together with the carbon atom to which they are attached form a group of formula (c) or (d); and R₈ is R'₈ is a direct bond or --CO--, --CH₂ CO--, --OCH₂ CO-- or --SO₂ --.
 13. A composition according to claim 8 wherein,R is R'where R'is hydrogen, methyl, formyl, C₁₋₄ alkylcarbonyl or --CO--CO--OC₁₋₄ alkyl; each R₁ and R₂ is methyl; R₄ is R'₄ and R₅ is R'₅ where either R'₄ is a direct bond, --NH--CO-- or --NH--CO--CH₂ --O-- and R'₅ is hydrogen or R'₄ and R'₅ together with the carbon atom to which they are attached form a group of formula (a) or (b); R₆ is R'₆ and R₇ is R'₇ where either R'₆ is --NH₂, mono- or di- C₁₋₄ alkylamino, C₁₋₂ alkylcarbonylamino or benzoylamino and R'₇ is hydrogen or R'₆ and R'₇ together with the carbon atom to which they are attached form a group of formula (c) or (d); and R₈ is R'₈ where R'₈ is a direct bond or --CO--, --CH₂ CO--, --OCH₂ CO-- or --SO₂₋₋.
 14. A composition according to claim 9 wherein,R is R' where R' is hydrogen, methyl, formyl, C₁₋₄ alkylcarbonyl or --CO--CO--OC₁₋₄ alkyl; each R₁ and R₂ is methyl; R₄ is R'₄ and R₅ is R'₅ where either R'₄ is a direct bond, --NH--CO-- or --NH--CO--CH₂ --O-- and R'₅ is hydrogen or R'₄ and R'₅ together with the carbon atom to which they are attached form a group of formula (a) or (b); R₆ is R'₆ and R₇ is R'₇ where either R'₆ is --NH₂, mono- or di- C₁₋₄ alkylamino, C₁₋₂ alkylcarbonylamino or benzoylamino and R'₇ is hydrogen or R'₆ and R'₇ together with the carbon atom to which they are attached form a group of formula (c) or (d); and R₈ is R'₈ where R'₈ is a direct bond or --CO--, --CH₂ CO--, --OCH₂ CO-- or --SO₂ --.
 15. A composition according to claim 13 wherein R₁₀ is R'₁₀ where R'₁₀ is hydrogen, methyl, chloro, bromo, C₁₋₂ alkoxy (max. 1 on a phenyl ring) or C₁₋₃ alkoxycarbonyl (max. 1 on a phenyl ring).
 16. A composition according to claim 14 wherein R₁₀ is R'₁₀ where R'₁₀ is hydrogen, methyl, chloro, bromo, C₁₋₂ alkoxy (max. 1 on a phenyl ring) or C₁₋₃ alkoxycarbonyl (max. 1 on a phenyl ring).
 17. A composition according to claim 3 wherein the pigment is of the formula ##STR54##
 18. A composition according to claim 4 wherein the pigment is of the formula ##STR55##
 19. A composition according to claim 4 wherein the pigment is of the formula ##STR56##
 20. A composition according to claim 4 wherein the pigment is of the formula ##STR57##
 21. A composition according to claim 4 wherein R₁₄, when it is other than hydrogen, is para to R₁₃ ; and R₁₅ is attached to the phenyl ring para to R₁₃ when R₁₄ is hydrogen and para to the azo moiety when R₁₄ is other than hydrogen.
 22. A composition according to claim 4 whereinR₁₃ is chloro, methoxy or C₁₋₂ alkoxycarbonyl, R₁₄ is hydrogen or chloro, and R₁₅ is --CO--NH-- or --SO₂ NH--.
 23. A composition according to claim 21 whereinR₁₃ is chloro, methoxy or C₁₋₂ alkoxycarbonyl, R₁₄ is hydrogen or chloro, and R₁₅ is --CO--NH-- or --SO₂ NH--.
 24. A composition according to claim 1 where the polymeric material is polyethylene, polypropylene, polystyrene, polyvinylchloride, natural rubber or synthetic leather.
 25. A composition according to claim 3 where the polymeric material is polyethylene, polypropylene, polystyrene, polyvinylchloride, natural rubber or synthetic leather.
 26. A composition according to claim 4 where the polymeric material is polyethylene, polypropylene, polystyrene, polyvinylchloride, natural rubber or synthetic leather.
 27. A composition according to claim 8 where the polymeric material is polyethylene, polypropylene, polystyrene, polyvinylchloride, natural rubber or synthetic leather.
 28. A composition according to claim 9 where the polymeric material is polyethylene, polypropylene, polystyrene, polyvinylchloride, natural rubber or synthetic leather.
 29. A composition according to claim 10 where the polymeric material is polyethylene, polypropylene, polystyrene, polyvinylchloride, natural rubber or synthetic leather.
 30. A composition according to claim 14 where the polymeric material is polyethylene, polypropylene, polystyrene, polyvinylchloride natural rubber or synthetic leather.
 31. A composition according to claim 1 wherein the pigment is present in an amount sufficient to stabilize the polymeric material against the effects of U.V. light.
 32. A composition according to claim 4 wherein the pigment is present in an amount sufficient to stabilize the polymeric material against the effects of U.V. light.
 33. A composition according to claim 26 wherein the pigment is present in an amount sufficient to stabilize the polymeric material against the effects of U.V. light.
 34. A composition according to claim 30 wherein the pigment is present in an amount sufficient to stabilize the polymeric material against the effects of U.V. light. 